NA - Home Instant Hot Water Recirculation Pump

SixPapaCharlie

May the force be with you
Joined
Aug 8, 2013
Messages
16,636
Display Name

Display name:
Sixer
I installed a water recirculation pump on my water heater so I can have instant hot water and not have to wait for the water to heat up.
We're wasting water waiting for it to get hot.

I attempted to find the furthest connection from the water heater by turning on a sink until it gets hot and then going to the other sinks to see which were hot.
I put the sensor valve under the kitchen sink and everything in the house has instant hot but my bathroom

So the question is for people running one of these systems, What happens if I add a 2nd sensor valve to the bathroom that isn't getting hot.
I am going to temp. relocate the valve to my bathroom but I suspect the kitchen will now be delayed.

I don't fully understand what that check/sensor valve is doing. I know it cross feeds the water from the hot to the cold side so there is no standing cold water in the pipes but I can't picture what it is really doing and I don't know if adding a 2nd one under my sink will fix it or add nothing to the puzzle.

Aside from the one bathroom, this system is great. Fully hot water from the moment you turn it on. Makes the bidet a little scary though.

Thanks in advance,
-Unemployed, Bored, 6PC
 
. . . Aside from the one bathroom, this system is great. Fully hot water from the moment you turn it on. Makes the bidet a little scary though.

Thanks in advance,
-Unemployed, Bored, 6PC
The potential for a boiled balloon knot does have a certain Russian roulette feel to it, lol.
 
The one I'm familiar with uses a circulator pump that runs on a schedule, not on a sensor. I disconnected it because I figured out how much energy I was using to heat all that hot water that was cooling down the pipes and heating up my house. Instant hot water is nice, but the water heater running non-stop is just too expensive to justify it. I also hated never having truly cold water (because the lukewarm water from the hot side gets pushed into the cold side), but in my experience Texas doesn't actually have cold water anyway. I suspect what you're talking about just replaces the timer with a sensor, so you could get what you want with another sensor, although it's going to mean heating even more water. Of course if you guys have expensive water and cheap energy, maybe it makes sense. Our water is free beyond the electricity to lift it out of the ground, but the propane to heat it is pricy.

Is the sensor you're talking about electrical, or is it just a thermostatic valve that bleeds hot water into the cold side?
 
The one I'm familiar with uses a circulator pump that runs on a schedule, not on a sensor. I disconnected it because I figured out how much energy I was using to heat all that hot water that was cooling down the pipes and heating up my house. Instant hot water is nice, but the water heater running non-stop is just too expensive to justify it. I also hated never having truly cold water (because the lukewarm water from the hot side gets pushed into the cold side), but in my experience Texas doesn't actually have cold water anyway. I suspect what you're talking about just replaces the timer with a sensor, so you could get what you want with another sensor, although it's going to mean heating even more water. Of course if you guys have expensive water and cheap energy, maybe it makes sense. Our water is free beyond the electricity to lift it out of the ground, but the propane to heat it is pricy.

Is the sensor you're talking about electrical, or is it just a thermostatic valve that bleeds hot water into the cold side?

Valve is not electric. just a thermostat.

1740436615341.png
 
I use cold water more often than hot water, so I'd rather wait for hot water than have lukewarm (or wait for) cold water. And the propane used to keep an uninsulated hot water pipe hot (I have a tankless heater). OTOH, as my pipes run together in a raceway on the perimeter of the house, it might keep the pipes from freezing in very cold weather... :idea:
 
my plumber says you can run a return line from the furthest hot line back to the water heater and plumb it to the heater "drain" with a check valve. It will naturally recirculate due to thermal differences.

But, like with life....you don't get anything for free. I'd imaging your electric bill will be a little more....but your water bill might be pennies less.
 
I just had a 4 gallon unit installed to speed up the hot water availability in our master bathroom. I hated having to get up in the middle of the night to hit the head then wash my hands with cold water. It was worth the install!! Also updated the ceiling vent fan to include a heater. The bride is happy and the new unit is very quiet.
 
Bosh makes a few different under-sink (or in-cloest, or under-floor, wherever you want to mount them) mini water heaters for this exact scenario, without much extra plumbing required. Just splice off the main hot supply line into the Bosch heater, out of the Bosch unit to the hot supply for the sink. Add a shunt/shutoff valve just AFTER the hot water splice that feeds the Bosch unit, and splice back in just after the shutoff valve. That way the first water to reach your sink is directly out of the mini water heater, and by the time it's empty it will be replenished from the main hot water supply line that feeds it. You're welcome.
 
That's a thing?
Yep. I built a bathroom in the hangar and only plumbed cold water to it. Got one of these at HD. Works great.

Can also put it in line with your hot water so the first water to the sink is hot and the heater under the sink is refilled with the hot water.

There are less expensive options on Amazon, as always…

IMG_7432.png
Add: there are true “tankless” options too. I looked at those but they needed more amperage plus I think the tank one gets hot water to the faucet quicker but they’re also an option.

 
Okay... that valve is interesting

81RGJCR1DuL._AC_SL1500_.jpg

I see no reason putting one in at each sink would be a problem. Seems like it would work great.
 
That's a thing?
Yup. My parents had one added under their kitchen sink when they ran into the same issue with long wait times. It only holds a few gallons but is hot instantly and by the time it runs out, the hot water from the main line has made it so there's no drop off.
 
Yup. My parents had one added under their kitchen sink when they ran into the same issue with long wait times. It only holds a few gallons but is hot instantly and by the time it runs out, the hot water from the main line has made it so there's no drop off.
OK, that's great.
I am going to try moving the valve and if it doesn't fix it, I am going to get one of those.
 
That's actually how it's done in most countries except here.
I have learned a lot of things that are done in other countries might be a little more logical.
I haven't bought toilet paper in 4 years. Dammit! I didn't mean to type that out loud on a pilot forum.
Once I am done hugging this tree, I will give my money to an insurance company. They need it more than me.
 
I have learned a lot of things that are done in other countries might be a little more logical.
I haven't bought toilet paper in 4 years. Dammit! I didn't mean to type that out loud on a pilot forum.
Once I am done hugging this tree, I will give my money to an insurance company. They need it more than me.
I'm not saying it's better, it's just how it's done typically in SE Asia. The typical home there doesn't have an over either. How the hell are you supposed to make a prime rib if you don't have an oven? It's like having pudding if you hadn't eaten your meat.

One thanksgiving, boss man managed to score a turkey from a restaurant guy that ordered some from the states. We didn't have an oven at the apartment, but we did have a gas grill brought over from Australia. I improvised and turned it in to an oven and we had turkey dammit think we didn't.

Our uh, translators... were amused by this weird American habit of cooking large pieces of animals for a long time in enclosed cooking spaces.
 
That's actually how it's done in most countries except here.
I lived in the Netherlands in 1980-81, and it has always blown my mind that we don't use the systems they do. There's a small tankless on-demand heater everywhere where hot water is wanted. You get hot water right away, you don't need to waste energy keeping a tank of water hot 24/7, and the house only needs half the plumbing. Here we are, 45 years later and we still haven't figured it out.

The typical home there doesn't have an oven either. How the hell are you supposed to make a prime rib if you don't have an oven? It's like having pudding if you hadn't eaten your meat.

One thanksgiving, boss man managed to score a turkey from a restaurant guy that ordered some from the states. We didn't have an oven at the apartment, but we did have a gas grill brought over from Australia. I improvised and turned it in to an oven and we had turkey dammit think we didn't.
Probably our most-repeated family story is from doing Thanksgiving in NL. My mom wanted to do a big feast with a bunch of our family friends over there, so she went to the local butcher and asked him to order a turkey. The "normal" turkeys there are tiny by our standards, and she kept rejecting what he had to offer in terms of their normal sizes and said, "Hoe groter, hoe beter!" (The bigger, the better)

Well, that butcher understood the assignment, and worked with one of his distributors to get his hands on one of the turkeys that was used to make those giant turkey breast loaf things. They are not normally sold at retail for reasons that would become obvious...

Well, it was the biggest damn turkey any of us normal people had ever seen, weighing in at a bit over 30 kilos (66 pounds)! She had to borrow a pan from a local hotel big enough to fit it. In fact, it still didn't fit, it stuck out over the sides and took up pretty much the entire volume of the oven. She also had it in a large oven bag (I think it may have been cobbled together from multiple bags) to keep it from dripping juices into the bottom of the oven from all the places it stuck out from that giant pan. They had to cobble something together to siphon juices from the bag because it kept expanding otherwise. There were several liters of gravy when all was said and done.

And we ate the turkey for Thanksgiving. We ate leftover turkey the next day (as you do). We had to use two families' freezers to store it all. We ate turkey for Christmas. We ate turkey for Easter. We ate turkey on several other occasions, and we finally ate the last of that turkey 9 months later the night before we hopped on a plane to come back stateside.

And that butcher is probably somewhere telling his grandkids about those crazy Americans and the giant turkey. :rofl:

Our uh, translators... were amused by this weird American habit of cooking large pieces of animals for a long time in enclosed cooking spaces.
I think it'd only take one good smoked brisket to make them see the light.
 
How the hell are you supposed to make a prime rib if you don't have an oven?
I dunno, I make a pretty mean beef roast on a (covered) grill.
I lived in the Netherlands in 1980-81, and it has always blown my mind that we don't use the systems they do. There's a small tankless on-demand heater everywhere where hot water is wanted. You get hot water right away, you don't need to waste energy keeping a tank of water hot 24/7, and the house only needs half the plumbing. Here we are, 45 years later and we still haven't figured it out.
If the alternative is an electrically heated tank, local on demand heaters make sense, if you have adequate electric wiring to the point of use. If the alternative is a fossil fueled heater, it might not make economic sense, unless the cost of fossil fuels is higher than electricity, perhaps that's part of the picture in Europe? I do know my propane fueled tankless heater costs significantly less to run than the well insulated electric tank it replaced.
 
Back
Top